A 'make then break' rotary switch question

[rooster]

Follow me down this rabbit hole for a minute. Let's talk about this type of switch in a NFB loop. If the switch was truly 'make then break', it seems to me that switching between two different resistive values connected to the PI tail could be accomplished without turning the amp 'OFF'. Say for example, one resistor was 50K and the other was 100K, in the instance that the two resistors connected to each other, the resistive value would be 33K, and then it would change to either the 50K or the 100K resistor as the switch reached the particular single resistor.

Tell me this then, if the connection is constant - no matter the resistance - why would the amp make a rather rude popping noise when the switch was rotated between resistors? Do I NOT have a 'make then break' switch, or is this something that will just happen no matter the switch? You have to put the amp in standby mode to make the NFB value change? Or is there another way to do this and avoid the 'popping'?

[LOUDthud]

There is a small amount of DC on the tail resistor and a small current flows through the feedback resistor into the OT. So it's gonna pop when you change the feedback resistor. When they added a Resonance control in the feedback loop, Peavey added an electrolytic cap (47uF IIRC) to remove DC from the pot.

If you run the inputs to the PI at ground by using a tail resistor that goes to a negative Voltage, you can remove the pop, but you can't apply feedback to the tail.

[rooster]

Thanks for the input, LOUDthud. Your explanation makes perfect sense. I will add that some of my confusion exists because the use of a continuous NFB pot doesn't seem to have a problem? My thinking was a 'make then break' switch would behave in a similar manner. Oh well.